LWCIntermediatejesttestinglms
Mock imperative Apex and LMS in Jest for integration test coverage
Real World Scenario
Component tests mock Apex but fail to catch LMS payload regression breaking downstream subscriber LWCs.
Expected Answer
• jest.mock on @salesforce/apex/apexMethod with resolved value
• createMessageContext mock for LMS publish subscribe tests
• Assert publishMessage called with expected payload shape
• Test subscriber handler updates DOM on message receive
• Mock Apex rejection testing error toast path
• Separate test files per concern: wire, imperative, LMS
• CI fails on jest --coverage below threshold for lwc js
Follow-Up Questions & Answers
Click to expand — each follow-up includes a direct, interview-ready answer
Direct answer: jest.mock on @salesforce/apex/apexMethod with resolved value Also consider: createMessageContext mock for LMS publish subscribe tests In practice: Assert publishMessage called with expected payload shape Balance speed of delivery with maintainability.
Architect Perspective
LMS contract tests prevent silent integration breaks—assert payload not only publish called.